Conventionally, air conditioners that cool and dehumidify the room are known (for example, see International Publication WO 03/029728). This type of air conditioner comprises a vapor compression refrigerant circuit having an outdoor heat exchanger as a heat source side heat exchanger and an indoor heat exchanger as an air heat exchanger, and a refrigerant is circulated in this refrigerant circuit to operate a refrigeration cycle. This air conditioner dehumidifies the room by setting the evaporation temperature of the refrigerant in the indoor heat exchanger lower than the dew point temperature of the room air and thus condensing moisture in the room air.
Also, dehumidifiers comprising a heat exchanger provided with an adsorbent on the surface thereof are also known (for example, see Japanese Patent Application Publication No. 07-265649). This type of dehumidifier comprises two heat exchangers each provided with an adsorbent. An adsorption process in which moisture in the air is adsorbed so as to dehumidify the air is performed in one of the two heat exchangers, while a regeneration process in which the moisture adsorbed is desorbed in performed in the other one of the two heat exchangers. During these processes, water that is cooled by a cooling tower is supplied to one heat exchanger that adsorbs the moisture, while heated wastewater is supplied to the other heat exchanger that regenerates water. Further, this dehumidifier is configured to supply the room with air that is dehumidified through the adsorption process and the regeneration process.